1. Field of the Invention
The subject matter disclosed herein relates to data updates to files and to anti-virus file scanning.
2. Description of the Related Art
Files are often scanned for computer viruses and other malicious software frequently referred to as “malware.” Such malicious software includes a variety of forms of hostile or intrusive software. Examples of malicious software include computer viruses, worms, trojan horses, and ransomware. Still other examples include spyware, adware, scareware, and other malicious programs. Malicious software can take the form of executable program code, scripts, active content, and other software. Malicious software is often disguised as, or embedded in, non-malicious files to facilitate the spread and to increase the difficulty in detecting the malicious software.
In some systems, upon a write operation to update a file, the write data is committed to the file to update the file, and an anti-virus scan is initiated on the updated file. Also in some systems, in order to facilitate the scanning process, a file to be scanned is subdivided into subfiles which are scanned separately by one or more scan servers. If the last write command introduces malicious software, the anti-virus scan can frequently detect it, and an attempt may be made to repair the infected file. If the repair of the infected file fails, the entire file is typically quarantined to prevent subsequent read operations to the infected file which can spread the malicious software. Hence, users are typically denied access to a quarantined file. However, a read operation directed to an infected file which has not been quarantined, may permit spread of the malicious software.